Re: [RFC] [PATCH] Allow overriding module parameters from kernel command_line

[Andrew Morton <akpm@linux-foundation.org>]

> On Wed, 18 Apr 2007 11:55:52 -0400 Kyle McMartin <kyle@canonical.com> wrote:
> With the move to initramfs and heavily modular configs, which include
> loading storage drivers from early userspace, it's becoming harder
> to provide users with a way of overriding module parameters at boot.
> 
> Currently, users would have to break into the initramfs, edit the
> modprobe options, and then let boot continue. They have a much easier time
> dealing with adding options on the command line from Grub or what have you.
> 
> I hacked out this patch quickly to re-parse saved_command_line[] when we
> load a module in an attempt to rectify this.
> 
> (The specific use-case I was looking at here was HPA commands failing on
>  sata_nv controllers, and needing to pass the adma=0 option to the module...
>  Users had a hard time testing without an easy way of overriding the module.)
> 
> Clearly this is not entirely optimal, because we're parsing command_line
> after the module params are parsed. This ends of being a policy decision,
> whether the /sbin/modprobe commandline should override the kernel
> command_line, or vice versa.

Similar-but-different: I was trying to persuade a Fedora system to use ext2
for the root filesystem the other day.  Turns out that we somehow managed
to break `rootfstype=' in this situation and it cheerfully continued to use
ext3.

Fixed by changing /etc/fstab and rebuilding initrd, but IMO rootfstype=
should have worked.